The Padres are pitching a lefty tonight, Eric Stults, and Brandon Belt is in the Giants’ lineup at first base.

No platoon here.

“He’s our everyday first baseman,” manager Bruce Bochy said. “He’s been swinging the bat better. He got a couple of hits last night, so he gets the starts. I’m not platooning at first. He’s feeling better at the plate, so we’ll see how he goes.”

Belt has six hits in 11 at-bats after opening the season 11-for-60. Joaquin Arias started at first against lefties Monday and Tuesday. He has one hit in his last 12 at-bats.

—– Left-handed reliever Jeremy Affeldt threw a 30-pitch bullpen session, and he could throw once more Monday when the team’s in Arizona. He’s eligible to be activated Tuesday. Since Jean Machi took Affeldt’s’ roster spot, he has tossed 3 2/3 scoreless innings of one-hit ball.

—– Another lefty reliever, Dan Runzler, has a 0.93 ERA and 11 strikeouts in 10 outings for Triple-A Fresno.

“Good for him,” Bochy said. “If he sustains this success for a while, he’ll force the issue.”

—– Marco Scutaro is hitting .217 and has three hits in his last 27 at-bats. FYI, another second baseman, Kensuke Tanaka, is hitting .392 in Fresno.